SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c086dc9a6244679df4511cdba349d758a5307cf9498cc1cc416e04e785567c' 
  AND token = 'TKs9PWO146FYEyXLVvWrDRpg7pULzZf2w9P2LYVqLTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}