SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '634bf677ee74329a6a9bf00409d3adda851f0d943ad760753c4f9092ff1d848a' 
  AND token = '4T/AOgjXYxrvMOoYqiBLRe2ZH9rsdEB67RIiiGcPf8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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