SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8efccc49cd3b3d561560253fa26ac2d7fb8e5daa3e60223c9754c9d3d37dff77' 
  AND token = '414d/HuVgFRz3w797Rej/B0sgDuO1UVlpLACibndnb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}