SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26628e69f33ff499886e02664ae633d0ceb07186aac5383889c5aaa722d09c32' 
  AND token = 'uPSKY+qNsZHURmZquDJ/GwXjNNBz+1g/if1BBh5kWio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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