SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e38974ecc5fb66f6513dbb01f13b7a2bdc764178cff3c3299e003b4182d23a07' 
  AND token = 'YeaEs4HPzBE48DK3/oF1LJg+20uj4dB5O/hGEVB8otc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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