SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f1400ecc95f9c51e07fa70a000a38eff5e00385670cdd252fc4be089b30b0db' 
  AND token = 'fwGmCZNcClAgIxI3ChtRd0E5g05Cnzc4j1d9VODt+qM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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