SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aead66d6141c6959d4784243511d2b6495be2032a225dc2dd08aee3a788995b9' 
  AND token = 'asQcQRmgqgmSm28pVHQga3ZHwgWNtBm4BaHAR67cDbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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