SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cbe5d642d0c8f8b149f34aef297612d91eb7ef0d590874b2e825111addcfd0b' 
  AND token = 'NxmCpQ1Vppez7tFBrTnKe//P+l/ZQ9GMXRPxFFJkwT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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