SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '204ae3f38d6f926950b4d1e660dce5906ccaa96cdb892dd00382bcb6e694d9ed' 
  AND token = 'rhU+HkokHO/ejb4jP9wkecgZ9iJiwMMa+d2SLiESbMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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