SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c9f2b0f171a3922c9756ed651f8469b6f895a23ce0b530daaeadcde6b3d2753' 
  AND token = 'XuQwDDOqqLL6LIU1YnF0rHztSvkl7iIuMXf/B27L+6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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