SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bede82f6146e895f282f247f90696a6e61cbf7a74f222dc1c7d17fee808354e' 
  AND token = '6ayK/5tslPfJUjCrCfKHUivYQ1GUMBqFJbzHbZPw9y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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