SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10479c214eb3afb4ac3768c475e5cb946e2376cca75950f242ae067091087a87' 
  AND token = 'ZyZhnwVra9bGLt6fL4BpqfVKLlo9yDWQDWgjy6mI+GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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