SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0a85e8889b744bf35ad27e045a6acef46646db1a969d6a415e5555cdcd89a7' 
  AND token = 'RiuSh0/m8Rm5c0RTHIXtYxIZhR5CDk05RDgfahdFzYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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