SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bccc6bf7dbeb4822bbea73014d131e424240efa47837c2924cbcce515f9a3ba2' 
  AND token = 'PD3BYsAFfQqaluJLu4UKyx+Tk5VjiS6yCmz/HsAIhqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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