SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86fd377c9a2cf88f6da464d561cad5ef5ef953c5ce7622beb6d23e9e7faba8f5' 
  AND token = '8AlxIDeS8b6eKnrLQt3xf9ndpo6J3V346N18Jyi0fk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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