SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5991ef49b2fbdc554b63956aae92d820eebc8a8abd32a55697c9a4080fd74109' 
  AND token = 'X7JW3A8c/mjiCLusi5fWxQWBNFywC8HDIOjSTHczZuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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