SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e97cf7141ddfd7f492542ea3241983203bb320bd06374684af2e25fedc03301' 
  AND token = 'ZD2pJ0q9B8iyF0IFt66/7XAGhbAAQkThYVrqgE54u9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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