SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9964cface397cee15e10454b90871573599bd906c62f15169942a178b3ed4e5' 
  AND token = 'JOB4M7ECawAM4m0oMLvNe2ZqCKlcVhRWx5yELBlJWkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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