SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a97402730bc1470b0034ce9d2b666386e7faaf9cdca7e6886871eaf86faade2f' 
  AND token = 'pDqanDIEGIJPJmHkPlPkfl1Q3R+hD5QmvNlWeIrTOX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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