SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bedd3f5f8e9a1f1ed1f4ff7287675b454410a2d96baa8d047a6dd9503a36639' 
  AND token = 'hkPKBcf1vSSdfU0q3gSaFCUGQZg3uts5bL2YGJJtKRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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