SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0a522a6f0d6428625f3a42865f3b5fda38f44dcdb33d3581b8615d620401999' 
  AND token = 'nSiX5G6vsNdD9/Gh43UIRvMxC4bhin2Isz8JXw+n8Dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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