SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e77615043a8f3baeb32703e15c4c83d565740bdad84a8a932807a51a757f011' 
  AND token = 'JIQ77waEBk+d/2SFkcUEbyYEHWaymyWBOjPV1eup3bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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