SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadd6ad515ebb34e1cd410f46f78d4f0c702fbae61174899ab66715ef1edf42d' 
  AND token = 'tiq11pCQPh6GyXLdpiCuNf+G9GoeOV+GzpZcZFHGBSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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