SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e228931744fa6ef003244d7c87f3ff80d864900f35f567016eaba9acdec75480' 
  AND token = 'gxBpNiqDXuVKdVgQLuBFpPKtZK7fr8pfZGEq6yv0+Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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