SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '997817fe1f6066820c0de7e4b23ad98e315921a904cc0d6fe6e15a623f5daca4' 
  AND token = 'nAbDpa/qOWiKzfY0q5aeKxeTqJbAL2zWTbloRZsYZC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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