SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c75f2363dc738f99745e7b06e0d004443d9231e895055594ab48796a3fcd26c2' 
  AND token = 'vCG/ivxjNk8R5QCDJ6t4bJ/2PIzFXRc82l+KGzbpIzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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