SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0df9bfaf9f33af51dd6e4d1dbe093278e6299b2c8a5b6de7b89395083dc74649' 
  AND token = 'JsgCVv/dpvjmtCSYfAIFO6BdrrBMPzIo3YjI1mFdCUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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