SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84f9f68579b2a1d75ecc3c14f28674f6a17df9516b6d17658531f68740ebfe11' 
  AND token = 'oYsgS3mEX5TnjN99AuXa/7KvsvjCKs1urN9EZVnCe4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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