SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73346a77d10136a7c791bc4d4be70b0141b60fcc5d07748526be0d1540cd7a93' 
  AND token = 'Lm33v/nGPRcA0ciShJx34JPpYHpA2fhKLJcYb1DSPCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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