SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a038cef7535863cd468de6193c73e0b4897ac6dcb1a2f38f921e530f2bdcdf6a' 
  AND token = 'k1c9qgER5YoFvwfU4GyQg/+fWieGNDJ/CPCPFh4QEjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}