SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97010cebb66b7e964b16b80682144cad6d968f15d8fd93c45a8c3bd1c448344d' 
  AND token = 'gR8QtK+RiK/NfBu5vjzh7Igr6MT0K1JGjGnb+qI92mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}