SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2543c6b7e75a8964e6fb064aa92aaa0c443533baaddfdd9fa8083f73a3b328e6' 
  AND token = 'AXW6oxSTXlZDzg5R/1ekG1PcZr2dqR5qYh528Y1vmmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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