SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c5bbf1d4620befa64e300289abea9de38f2171621901f1218325161ef8c78b' 
  AND token = 'OuZzfCoMfaGkAmAXU5cmnI2PCwtai094GiR40+1cp+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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