SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df20afca25e49e36892bd8254a32e3ed3c23203ca9f7e52659b87275314a1667' 
  AND token = '7M6S+hK5HZ5Vj0Jg6dxowYIx5H+RItwLhZMpV8sdr1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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