SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25cb8881b118651d6221c08f625d0d5846b3c826e67ba7d90ab32b2446bb1b3e' 
  AND token = 'FGhsrzfUwkqLkwrF57pFlwpwBBIBSnKfH5V5zV3ddYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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