SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2115ae88a53a156a59638834dbd7fda4cd61e257d4ecd749a33c55f489c6d5a8' 
  AND token = '+vMJvSGZjxYxZKaVvXOq4H6E8oOs7Q8nu0N2+D3YwtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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