SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe59af1539ef948f51eb12ad515188622e2eb63fe944426be989e76c0f14c11c' 
  AND token = 'YYtY5Fhv3K2zrdHI66R2VgYg3y2ZCBQUSumqHESCxsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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