SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd5989d4dd45e2bb1a4b44514cd5924878ff30ab205657d9fb105d984966cebc' 
  AND token = 'FRPElf1tKTZblCIpX6B1bB1xK364fGTfw76fAFMBZf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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