SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'de430cc5affca06697aab4639845963d866834a378cd376d0b9565cd1102c277' 
  AND token = 'rFZhZ+PreL5doHdtYoxq/tMKOQeccjWyLhN6AH4Rd6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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