SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7c43c497806fb8d6f8f9385999bd46dda216f4fd89f4f2d253e03afc78db034c' 
  AND token = 'WBPgxM3kVP39CLfw7XfgILpqiSI+jRP2Ywdv/UmFLk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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