SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4d076c8c3fecc923954638e9c02841e6aae8034bcd542e17089c385d3048e93' 
  AND token = 'AOLYTgs9BBuL9bnuhCS4WWeUKAEF4kUbqrwu8N55bbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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