SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba3f7f679f9f1e4931c88dba31ca982379df624879575ec1a8f4a7e08ba76f93' 
  AND token = 'WqdJvENn8TNpNvtiTUkqtuJwaEdPxgC2A2ftnW1C13o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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