SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c8d4e2069940f58eeee89efbcdfb372e74d639e2d537cc3815c5deda2961073' 
  AND token = 'ELnKY7KVk/Oxuv2A41ncfMwPkCDakO860KQz6duAe/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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