SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '123ccc3d61cef72c0547526bcdde3ad79a1a0a58ae6e1ddc09fcfaf3ff54d677' 
  AND token = '+AV+DcRtZsLjTLmjV7F4loW139LGVi44DtLkDCPr6zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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