SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be080797cbf9197222544280b4844af285717ce0b684e32d8a0af9f5f80fd2a' 
  AND token = 'RndnzYDTuE0VJ4h0gJvNCMniztaeUM5ZaYOra98w0mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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