SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e163e7b672f2c8e8a1b6b07a4eaff7726be882277888b9a2c2897a0e7e9295f' 
  AND token = 'LStZOneiZBKBfeOv+1g/NOmbPKMusP3/gr7p6B3QmOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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