SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1d406f5dc1c9ce3e74cba0b21674129e79692db720129405bf4c5cef0a388262' 
  AND token = 'Tx/W/iJR4u2S9+vDZsexWzdKEscSp74LZMsWRCflIcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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