SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72f9ccab2002a699a1c3315428963c94c66576851807631e509252ca1339144d' 
  AND token = '3gZEyTSD67ir8H8xD2mm0gNLoTFA7tY2VloEQBs3cpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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