SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c01d1b16217fa785f15105a156489a70ff2a24ae43c9caec5de02cbaa01405b7' 
  AND token = 'jeUXNMPKpLz8ePW1BnJgBFGM/TMlHbrmtkuuq91JxEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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