SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dee0b3f3fbb38516ee99b913c1090e54657b8d44b062a405afe496d9808b3c1' 
  AND token = '3bkbhQfgPmHogAkyERjF/9PjBXl5SEyrWsh3wzrGbjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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