SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bbb2b4a017a83b84cd55d70ced1d3312343b2108553de922e7a6d2a02f4e6f6e' 
  AND token = 'kPhBbpAB19hsiOAtQbKC5UQLYpdBqzHZmqXGpdAb4Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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