SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f05998b94882ba64c50121b5e0d79572fbc5826136d8214ef9474431f32c521' 
  AND token = 'G/e28FOChGnaVx3W4GRHXcKoIxq1/hQJl5gCnCdM7tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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