SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b660be3fef932c1aa9b3d1e29444d03f929a25c7a6ae9685ead77e20167f385' 
  AND token = 'XUPMwX35QTh5R8RD6y4UQiqFvxPB4olXh43AiXXqYXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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