SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '915a68e55b5d903874acaec3c7d5204a907c8254b529e5f2516f71362728d705' 
  AND token = 'NvBkd1q2BjL+ZSoM/CqdzZoPB3f0NO66pGwlR2Fv6zY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}