SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37089cf4fe1b0a7518094e0532411e3745a59fb0b22982782226579b486d5fad' 
  AND token = 'uu6zxk2BuZYba9Wi6B8HNCahlmuTKUtL9Bncp8Hgkt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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