SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8ba84f6d3ee14c3e007076d314939601618fcb0910382e84b312a6fdd3df89b' 
  AND token = 'rPk4MyljJJj0gqpyNLzSTJj1dpLi+VIWSEiEES0Hhl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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