SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e55b71384d212a524b20f4f4c82be58e473a79cc45c74f896f32ddaa7cf81e2a' 
  AND token = 'KrV2zS8XAZFWwhEnMpSzYCjlmnnmmqcZpXzp8Mjy1yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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