SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7933514d34af16a50bfe3b789cadd5bef94692e04d5322034e94bffb9bb787a2' 
  AND token = 'BflVoaR4FnZlDwBXwzQWeupCT5GyIez4RmrYPJItxAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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