SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7fe7687dd543c989edbb8d3f33d208484defb0287df700e8edcd4f0d4378ea' 
  AND token = 'WeqoXEJLeaoEZwBR12US0aRt4rQQdS46pvNOP4BEKmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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