SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbe338ee524c7795bf50c7dd15986578dc9159cc2186bd2849c139b36c33210b' 
  AND token = 'BNffhKmSgCwr/Zl1A1qZAz8ATknTajLyEIGTheDa9wo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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