SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c01fd81d5159cfde0974860c988c93cbca32c384321a009cb50045d2bda87b8b' 
  AND token = 'XYgaC1FUjCBmdJLvs4JqVwkIcaREspI+QaK377g3rAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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