SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c459a9060083e8927f7b33e76693b261012ace96623c3cc33befe4d23e5916d0' 
  AND token = 'N9Tim7mJb7mqXfxkWJHMscCesHvWYJcUXzKW1SB6LRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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