SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a88adca6e496a416506ff3b5689fd279adc3a1d3f741d4234e3ba59a4b830c02' 
  AND token = 'OaP1hrQ9dClR4IfKFDZ69vKtrILhXM/0l07p23dMw6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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