SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43cdfa7eb521bf304f679c0965a21f8bd3a5b08722a2f2f3582ec2c3cf4c2a5a' 
  AND token = 'urRn/LlXgjP1FhZvmDqs4xQvpCOwhBRemMRFUt6HqqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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