SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc7741c3275b6347fd7e3652c159006c457763d85471bab3094e916bfefcbc99' 
  AND token = '32dDeMq9xNczStT37x2QBwidDcVMx+f2UbkbXUPosNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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