SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c7ec7fbe38638295d106b0d990b77833657423f316894ea4370838992a7899a' 
  AND token = 'swg9Vi+6OFltfzcueOUvJJImKVQEhBOFgP6UgC8wv/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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